After 8 minutes on incline treadmill felt chest pain. is this an indicator of cardiac problem? i couldn't continue?

Exercise should be undertaken in a gradual increase. Starting a vigorous exercise program without building up to it can yield pain & shortness of breath. If you feel like you have been gradually increasing your time on the treadmill and suddenly you are experiencing chest pain, then you should see a Dr. for a full evaluation. If this episode happened when you were overdoing it, try slowing down.

If you developed chest while exercising and could not continue you essentially had an unmonitored exercise stress test. You need to follow up with a cardiologist since you probably need a stress test (you exercise on the treadmill while monitored). No strenuous activity until you are cleared.